Apparatus and methods for restoring tissue

ABSTRACT

An apparatus and methods tissue restoration are provided. The apparatus may include a catheter shaft extending from a proximal end to a distal tip and a translucent first distal balloon positioned on a translucent distal segment of the catheter shaft inside of and concentric with a second distal balloon proximal to the distal tip in fluid communication with a drug source via a first lumen, the first distal balloon may include first and second outer surfaces, and longitudinal and circumferential channels. A first light fiber and a second light fiber each positioned in the catheter shaft and extending through the translucent distal segment. The drug source provides at least one drug to the first distal balloon via the first lumen.

BACKGROUND Technical Field

The present disclosure generally relates to apparatus and methods torestore a tissue's function. More particularly, and without limitation,the disclosed embodiments relate to catheters, and catheter systems tocreate a natural vessel scaffolding and restore tissue function.

Background Description

Balloon catheters are used in a number of surgical applicationsincluding occluding blood flow either distally or proximally of atreatment site. The inflation of the balloon must be controlled in orderto avoid over-expansion or breakage of the balloon, which may rupture orotherwise damage the vessel. Percutaneous Transluminal Angioplasty(PTA), in which a balloon is used to open obstructed arteries, has beenwidely used to treat atherosclerotic lesions. However, this technique islimited by the vexing problems of re-occlusion and restenosis.Restenosis results from the excessive proliferation of smooth musclecell (SMC), and the rate of restenosis is above 20%. Thus, about one infive patients treated with PTA must be treated again within severalmonths.

Additionally, stenting is a popular treatment, in which a constrictedarteriosclerotic segment of the artery is mechanically expanded with theaid of a balloon catheter, followed by placement of a metallic stentwithin the vascular lumen to restore the flow of blood. Constriction orocclusion of the artery is problematic and can be itself, or cause, amajor health complications. Placement of a metallic stent has been foundto result in the need for postoperative treatment in 20% to 30% ofpatients. One cause of this high frequency of required postoperativetreatment is vascular intimal hyperplasia within the vascular lumenresulting in lumen narrowing despite the stent being placed. In order todecrease in-stent restenosis, attempts have been made to design a stentof a type having a surface carrying a restenosis-inhibiting drug so thatwhen the stent is placed in an artery, the drug is eluted in acontrolled manner within the vascular lumen. Those attempts have led tocommercialization of drug-eluting stents (hereinafter referred to asDES) utilizing sirolimus (immunosuppressor) and paclitaxel (cytotoxicantineoplastic drug). However, since those drugs have an effect ofinhibiting the proliferation of vascular cells (endothelial cells andsmooth muscle cells) by acting on the cell cycle thereof, not only canthe vascular intimal hyperplasia resulting from an excessiveproliferation of the smooth muscle cells be suppressed, butproliferation is also suppressed of endothelial cells once denudedduring placement of the stent. This can result in the adverse effectwhere the repair or treatment of the intima of a blood vessel becomesreduced. In view of the fact that thrombosis tends to occur more easilyat a site less covered with endothelial cells in the intima of a bloodvessel, an antithrombotic drug must be administrated for a prolongedtime, say, half a year or so and, notwithstanding this antithromboticdrug administration, a risk of late thrombosis and restenosis will occurupon its discontinuance.

The technical problem addressed by the present disclosure is thereforeto overcome these prior art difficulties by creating devices providingfor controlled delivery of therapeutic agents to the surroundingtissues, propping the vessel open to a final shape, and functionalizingthe therapeutic agent within the tissue and forming the cast shape,permitting blood flow and restoring tissue function. The solution tothis technical problem is provided by the embodiments described hereinand characterized in the claims.

SUMMARY

The embodiments of the present disclosure include catheters, cathetersystems, and methods of forming a tissue scaffolding using cathetersystems. Advantageously, the exemplary embodiments allow for controlled,uniform delivery of therapeutic agents to the surrounding tissues,casting the tissue to a final shape, and functionalizing the therapeuticagent in the tissue, forming the cast shape and propping the vesselopen. The tissue may be a vessel wall of a vessel within thecardiovascular system.

According to embodiments of the present disclosure, an apparatus isprovided. The apparatus may include a catheter shaft extending from aproximal end to a distal tip and a first distal balloon positioned on atranslucent distal segment of the catheter shaft proximal to the distaltip and positioned inside of and concentric with a second distalballoon. The first distal balloon may be in fluid communication with adrug source via a first lumen. The first distal balloon may include atranslucent material, a plurality of longitudinal channels recessed froma plurality of outermost radial surfaces of the first distal balloon,and a plurality of circumferential channels recessed from the outermostradial surfaces of the first distal balloon. The apparatus may include asecond distal balloon in fluid communication with a second lumenseparate from the first lumen, and a first light fiber and a secondlight fiber each positioned in the catheter shaft and extending throughthe translucent distal segment.

In some embodiments, the second distal balloon includes a plurality ofslitted apertures radially aligned with the outermost radial surfaces ofthe first distal balloon, the slitted apertures selectively communicatethe drug from the first distal balloon to a treatment area of a subject.The slitted apertures may be positioned away from the longitudinalchannels and the circumferential channels of the first distal balloon.The slitted apertures of the second distal balloon may remain in contactwith the outermost radial surfaces of the first distal balloon, sealingthe slitted apertures closed during inflation and deflation of the firstdistal balloon. During inflation of the second distal balloon, the fluidfills between an inside surface of the second distal balloon and anoutside surface of the first distal balloon, gradually filling thelongitudinal channels and circumferential channels. A pressure of thefluid between the inside surface of the second distal balloon and theoutside surface of the first distal balloon increases and inflates thesecond distal balloon, the increased pressure forces edges of theslitted aperture to open apart thereby reducing the pressure. Inflationof the second distal balloon moves the slitted apertures away from theoutermost radial surfaces of the first distal balloon allowing theslitted apertures to open and permit fluid flow to the treatment area.

In some embodiments, the translucent material of the distal segment, thefirst distal balloon, and the second distal balloon is transparent. Thefirst light fiber and the second light fiber may provide lightactivation through the distal segment, the first distal balloon, and thesecond distal balloon. The longitudinal channels and circumferentialchannels are non-deformable and provide uniform drug delivery throughthe second distal balloon. The second distal balloon may includematerial that conforms to the morphology of the vessel wall.

Embodiments of the present disclosure also provide a method of tissuerestoration in a blood vessel of a subject. The method may includeproviding a catheter into the blood vessel. The catheter may include acatheter shaft extending from a proximal end to a distal tip and a firstdistal balloon positioned on a translucent distal segment of thecatheter shaft proximal to the distal tip and positioned inside of andconcentric with a second distal balloon. The first distal balloon may bein fluid communication with a drug source via a first lumen. The firstdistal balloon may include a translucent material, a plurality oflongitudinal channels recessed from a plurality of outermost radialsurfaces of the first distal balloon, and a plurality of circumferentialchannels recessed from the outermost radial surfaces of the first distalballoon. The apparatus may include a second distal balloon in fluidcommunication with a second lumen separate from the first lumen, and afirst light fiber and a second light fiber each positioned in thecatheter shaft and extending through the translucent distal segment. Themethod may include supplying a drug from the drug source to the firstdistal balloon, delivering the drug to the treatment area through theslitted apertures, and activating the first light fiber and the secondlight fiber thereby providing light transmission through the distalsegment, the first distal balloon, and the second distal balloon toactivate the drug in the treatment area.

The method may further include gradually filling the drug into a volumeof the longitudinal channels and circumferential channels between aninside surface of the second distal balloon and an outside surface ofthe first distal balloon, and expanding the second distal balloon,thereby moving the slitted apertures away from the outermost radialsurfaces of the first distal balloon. The method may further includecontracting the second distal balloon as fluid is delivered through theslitted apertures. Contracting the second distal balloon may move thesecond distal balloon into contact with the outermost radial surfaces ofthe first distal balloon and closes the slitted apertures, causing drugdelivery to stop.

Embodiments of the present disclosure also provide an apparatusincluding a catheter shaft extending from a proximal end to a distal tipand a first distal balloon positioned on a translucent distal segment ofthe catheter shaft proximal to the distal tip and positioned inside ofand concentric with a second distal balloon. The first distal balloonmay be in fluid communication with a drug source via a first lumen. Thefirst distal balloon may include a translucent material, a plurality oflongitudinal channels recessed from a plurality of outermost radialsurfaces of the first distal balloon, and a plurality of circumferentialchannels recessed from the outermost radial surfaces of the first distalballoon. The apparatus may include a second distal balloon in fluidcommunication with a second lumen separate from the first lumen, and afirst light fiber and a second light fiber each positioned in thecatheter shaft and extending through the translucent distal segment. Thedrug source is configured to provide at least one drug to the firstdistal balloon via the first lumen and during inflation of the seconddistal balloon, the fluid fills between an inside surface of the seconddistal balloon and an outside surface of the first distal balloon,gradually fills the longitudinal channels and circumferential channels.

Additional features and advantages of the disclosed embodiments will beset forth in part in the description that follows, and in part will beobvious from the description, or may be learned by practice of thedisclosed embodiments. The features and advantages of the disclosedembodiments will be realized and attained by the elements andcombinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are examples and explanatory only andare not restrictive of the disclosed embodiments as claimed.

The accompanying drawings constitute a part of this specification. Thedrawings illustrate several embodiments of the present disclosure and,together with the description, serve to explain the principles of thedisclosed embodiments as set forth in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of an exemplary apparatus including acatheter, according to embodiments of the present disclosure.

FIG. 2 is a side elevational view of a distal portion of the catheter ofFIG.

FIG. 3 is a perspective view of an exemplary first balloon of theexemplary catheter of FIG. 1.

FIG. 4 is a perspective view of an exemplary second balloon of theexemplary catheter of FIG. 1.

FIG. 5A is a cross-sectional view taken along line 5A-5A of FIG. 2.

FIGS. 5B and 5C are cross-sectional views taken along line 5B-5B of FIG.2A, removing portions of the external structure.

FIG. 6 is a perspective detailed view of the first balloon of FIG. 3.

FIG. 7 is a perspective cross-sectional view from line 6-6 of FIG. 4,removing portions of the internal structure.

FIGS. 8A-8F show a series of internal perspective views illustrating afilling sequence in accordance with embodiments of the presentdisclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments and aspects of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Where possible, the same reference numbers willbe used throughout the drawings to refer to the same or like parts.

FIG. 1 illustrates an apparatus 100 in accordance with an embodiment ofthis disclosure. The apparatus 100 having a catheter shaft 104 thatextends from a proximal end 106 to a distal tip 110 of the apparatus100. The apparatus 100 may be configured for longitudinal movement andpositioning within a vessel (e.g. blood vessel) of a subject. In someembodiments, the apparatus 100 may be configured for treatment of anarea of the vessel. In some embodiments, the apparatus 100 may occludethe vessel, while in other embodiments the apparatus may not occlude thevessel. For example, the apparatus 100 may be configured for delivery ofa drug to an area of the vessel occupied by the apparatus 100 which mayform and cast a shape in the vessel, as will be described in more detailbelow.

The apparatus 100 may include a proximal end connector 114 positioned atthe proximal end of the apparatus 100, and the catheter shaft 104 mayextend in a distal direction therefrom. The catheter shaft 104 maydefine a plurality of lumens that are accessible via a plurality ofports the proximal end connector 114. The plurality of ports 115 may beconfigured to engage with external sources desirable to communicate withthe plurality of lumens. The ports may engage with external sources viaa variety of connection mechanisms, including, but not limited to,syringes, over-molding, quick-disconnect connectors, latchedconnections, barbed connections, keyed connections, threadedconnections, or any other suitable mechanism for connecting one of theplurality of ports to an external source. Non-limiting examples ofexternal sources may include inflation sources (e.g. saline solutions),gaseous sources, treatment sources (e.g. medication, drugs, or anydesirable treatment agents discussed further below), light sources,among others. In some embodiments, apparatus 100 can be used with aguide wire (not shown), via guide wire lumen 164 (see FIG. 5A), toassist in guiding the catheter shaft 104 to the target area of thevessel.

FIGS. 1, 2, and 3 illustrate the apparatus 100 may include a firstdistal balloon 120 positioned inside of and concentric with a seconddistal balloon 122 over a distal segment 130 of the catheter shaft 104proximal to the distal tip 110. In some embodiments, the first distalballoon 120 may be proximally offset from the distal tip 110 a distancebetween 0 mm and 1 mm, 0 mm and 2 mm, 0 mm and 3 mm, 0 mm and 10 mm, or0 and 50 mm. The first distal balloon 120 may take any shape suitablefor supporting a wall of a blood vessel or other hollow body structureof the subject when the compliant or semi-compliant balloon is inflated.

The second distal balloon 122 may have one continuous surface sealed ateach end around the catheter shaft 104 forming an enclosed volume and influid communication through a port with the catheter shaft 104 through adistinct and separate lumen from the first distal balloon 120. Thesecond distal balloon 122 may be substantially translucent. In someembodiments, the second distal balloon 122 may inflate to 2 to 10millimeters (mm) in diameter. In other embodiments, the second distalballoon 122 may inflate to 1 to 8 cm in diameter. The second distalballoon 122 may have a length of about 0.5 to 1 centimeters (cm), 1 to 2cm, 1 to 3 cm, or 1 to 5 cm, or 1 to 10 cm, or 1 to 15 cm, or 1 to 20cm, or 1 to 25 cm, and may take any shape suitable for supporting a wallof a blood vessel of the subject when the non-compliant orsemi-compliant balloon is inflated. For example, the second distalballoon 122 may expand into a cylindrical shape surrounding the distalsegment 130 of the catheter shaft 104. The cylindrical shape may begradually tapered inward at a proximal end and a distal end of thesecond distal balloon 122, thereby providing a gradually taperedproximal end and distal end of the second distal balloon 122 that taperinto contact with and become flush with the catheter shaft 104.

Non-limiting examples of shapes the inflated second distal balloon 122may form include a cylindrical shape, football-shaped, spherical,ellipsoidal, or may be selectively deformable in symmetric or asymmetricshapes so as to limit the potential difference in the treated vesselshape and the untreated vessel shape reducing edge effects commonbetween two surfaces of different stiffness as found in metal stents.The force exerted against a vessel interior by second distal balloon 122may be strong enough to scaffold the vessel wall with the apparatus 100held in a stationary position within the vessel or other hollow bodystructure. However, the force is not so great as to damage the interiorsurface of the vessel or other hollow body structure.

The apparatus 100 may include a plurality of connectors 115 positionedproximally to the proximal end connector 114. For example, the firstdistal balloon 120 may be terminated at the proximal end with aconnector capable of receiving a drug source. In some embodiments, theconnector may be a luer configuration. The second distal balloon 122 maybe terminated at the proximal end with a separate and distinct connectorcapable of receiving a fluid for inflation, which may, in someembodiments, be a luer configuration. A center lumen (discussed in moredetail below), may be terminated at the proximal end with a connectorcapable of receiving a fluid source for clearing the lumen from theproximal termination to outside the distal tip, and in some embodimentsmay include a luer configuration. The center lumen may also accommodatea guidewire for tracking the catheter apparatus to the desiredanatomical location. As discussed in more detail below, the apparatus100 may also include light fibers that may be terminated at the proximalend with an adaptor capable of connecting with a light source. Eachlight fiber may terminate with a separate and distinct adaptor or eachlight fiber may share an adaptor to a light source.

The materials of the apparatus 100 may be biocompatible. The cathetershaft 104 may include material that is extrudable and capable ofsustaining lumen integrity. The distal segment 130 of the catheter shaft104 is substantially translucent to allow light transmission from lightfibers. The catheter shaft 104 material is rigid enough to track over aguidewire and soft enough to be atraumatic. The catheter shaft 104 maybe made of materials including, but not limited to polymers, natural orsynthetic rubber, metal and plastic or combinations thereof, nylon,polyether block amide (PEBA), nylon/PEBA blend, thermoplasticcopolyester (TPC), a non-limiting example may be HYTREL® (available fromDupont de Nemours, Inc. of Wilmington, Del.), and polyethylene. Theshaft materials can be selected so as to maximize column strength to thelongitudinal length of the shaft. Further, the shaft materials can bebraided, so as to provide sufficient column strength. The shaftmaterials can also be selected so as to allow the device to movesmoothly along a guide wire. The catheter shaft 104 can also be providedwith a lubricious coating as well as antimicrobial and antithrombogeniccoatings. The shaft materials should be selected so as not to interferewith the efficacy of the agent to be delivered or collected. Thisinterference may take the form of absorbing the agent, adhering to theagent or altering the agent in any way. The catheter shaft 104 of thepresent disclosure may be between about 2-16 French units (“Fr.” whereone French equals ⅓ of a Millimeter, or about 0.013 Inches). TheCatheter shafts to be used in coronary arteries may be between about 3-5Fr. in diameter, and more specifically may be 3 Fr. The catheter shaftsto be used in peripheral vessels may be between about 5-8 Fr. indiameter, and more specifically 5 Fr. The catheter shafts to be used inthe aorta may be between about 8-16 Fr. in diameter, and morespecifically 12 Fr.

The first distal balloon 120 and the second distal balloon 122 may besubstantially translucent permitting light from light fibers to betransmitted substantially beyond the inflated diameters of the seconddistal balloon 122. The second distal balloon 122 may be compliant suchthat the material conforms substantially to a vessel's morphology. Thefirst distal balloon 120 material may be more rigid and noncompliant,capable of higher internal pressures with minimal outward expansion foropening vessels that are more resistant to pressures. The compliance ofthe first distal balloon and second distal balloon may be comparable ordissimilar. For example, the first distal balloon 120 may benon-compliant, capable of higher internal pressures with minimal outwardexpansion for propping open and casting a vessel into optimal shapes.The second balloon 122 material may be elastic, capable of covering thefirst distal balloon 120 as a skin or covering, expanding andcontracting with the inflation of the first distal balloon 120 andelastically conforming substantially to a vessel's morphology foroptimal drug delivery. The second distal balloon 122 may includematerial that conforms to the morphology of the vessel wall therebyproviding optimal drug delivery in a non-dilating and non-traumaticmanner. The apparatus 100 may not cause any further trauma (e.g. traumacaused by atherectomy or percutaneous transluminal angioplasty “PTA” orvessel preparation methods) to the vessel to promote optimal healing.

The balloons may be thick or thin for performance optimization. Thefirst distal balloon 120 may be thicker (0.002 inches) to better formthe fluid channels and prop the vessel wall for shaping. The seconddistal balloon may be thicker (0.002 inches) to better form the openingand closing function of the perforations 198 described in more detailbelow.

FIG. 3 is a perspective view of the first distal balloon 120 with thesurrounding second distal balloon 122 removed. In some embodiments, thefirst distal balloon 120 may not be a percutaneous transluminalangioplasty balloon or a high-pressure apparatus, but instead the firstdistal balloon 120 may be non-dilating and used for vessel shape formingor propping a vessel open. The first distal balloon 120 includes aplurality of longitudinal fluid channels 124 and a plurality ofcircumferential fluid channels 126. The longitudinal fluid channels 124extend along the length of the first distal balloon 120, eachlongitudinal fluid channel 124 being spaced apart from otherlongitudinal fluid channels 124 and each longitudinal fluid channel 124intersecting with a plurality of circumferential fluid channels 126along the length of the first distal balloon 120. The longitudinal fluidchannels 124 and the circumferential channels 126 may intersect at anangle from 10° to 170°. The circumferential fluid channels 126 extendaround the circumference of the first distal balloon 120, eachcircumferential fluid channel 126 being spaced apart from othercircumferential fluid channels 126. The longitudinal fluid channels 124and the circumferential fluid channels 126 each having a depth, wherethe depth of the fluid channels is measured in relation to an outersurface 127 of the first distal balloon 120. Accordingly, thelongitudinal fluid channels 124 and the circumferential fluid channels126 are recessed from the outer surface 127 of the first distal balloon120. The depth of the longitudinal fluid channels 124 and thecircumferential fluid channels 126 may be the same depth or differentdepths. The longitudinal fluid channels 124 and the circumferentialfluid channels 126 may be non-deformable. In some embodiments, the fluidchannels 124, 126 promote the first distal balloon 120 to fold.

FIG. 4 illustrates the second distal balloon 122 that may includematerial that is substantially translucent and elastic, capable ofremaining in contact with the outermost radial surface of the firstdistal balloon 120, and may act as a covering or skin of the firstdistal balloon 120, during inflation and deflation of the first distalballoon 120. The second distal balloon 122 may include a plurality ofperforations 198 penetrating through the balloon wall. The perforations198 may be slitted apertures. The slitted apertures 198 may be in fluidcommunication from the inside surface of the second distal balloon 122to the outside surface of the second distal balloon 122, as described inmore detail below. The perforations 198 may be formed in an inflated orexpanded material state whereupon in a deflated or contracted state theperforations remain naturally closed.

FIG. 5A is a cross-sectional view taken along line 5A-5A of FIG. 2showing a plurality of lumens within the assembly 100, according to anembodiment of this disclosure. The catheter shaft 104 may have anoutside diameter and outside surface 130. The catheter shaft 104 mayhave an inside configuration of five distinct and separate lumens,extending from the proximal end 106 to the distal tip 110.

The first distal balloon 120 may be in fluid communication with a firstdistal balloon inflation lumen 150. The second distal balloon 122 may bein fluid communication with a second distal balloon inflation lumen 154that is separate and distinct from the first distal balloon inflationlumen 150. The first distal balloon 120 may be in fluid communicationwith an inflation source via the first distal balloon inflation lumen150 separate from the second distal balloon inflation lumen 154. Thefirst distal balloon inflation lumen 150 may extend through the cathetershaft 104 and have an input at one of the plurality of ports 115 of theproximal end connector 114. Fluid communication between the first distalballoon 120 and the inflation source via the first distal ballooninflation lumen 150 may cause the first distal balloon 120 toselectively fill separately from and independently of the second distalballoon 122. Similarly, the second distal balloon 122 may be in fluidcommunication with an inflation source via the second distal ballooninflation lumen 154 separate from the first distal balloon inflationlumen 150. Fluid communication between the second distal balloon 122 andthe inflation source via the second distal balloon inflation lumen 154may cause the second distal balloon 122 to selectively inflate anddeflate separately from and independently of the first distal balloon120.

A first light fiber lumen 158 and a second light fiber lumen 160 may bepositioned in the catheter shaft 104 to receive light fibers, and thefirst light fiber lumen 158 and the second light fiber lumen 160 mayextend from the proximal end 106 into the distal segment 130, and may bepositioned substantially symmetric, longitudinally opposed and parallelone to another within the catheter shaft 104. In another exemplaryembodiment, the catheter shaft 104 may include a single light fiberlumen. In still other embodiments, the catheter shaft 104 may include aplurality of light fiber lumens.

A guidewire lumen 164 may be concentric with the catheter shaft outsidediameter and may be arranged in the catheter shaft 104, from theproximal end 106 through the distal tip 110. The guidewire lumen 164 mayaccommodate a guidewire to aid the placement of the apparatus 100 to adesired anatomical position communicating with the proximal end anddistal tip. The guidewire may be separate and distinct from theapparatus 100 and extend proximally beyond the proximal end and distallybeyond the distal tip of the catheter shaft. The guidewire lumen 164 islocated concentric with the catheter outer diameter; the catheter shaftis oriented concentrically with the guidewire permitting the cathetershaft 104 to follow the guidewire without favoring one side of thecatheter shaft 104 or whipping from side to side. The guidewire mayremain in the guidewire lumen 104 maintaining anatomical position duringthe activation of the light fibers.

FIGS. 5B and 5C illustrate cross-sectional views taken along line 5B-5Bof FIG. 2. The apparatus 100 may further include a first light fiber 140and a second light fiber 142 positioned in the catheter shaft 104 andextending through the distal segment 130. The light fibers 140, 142 maytransmit light through the distal segment 130, the second distal balloon122, the first distal balloon 120. The light fiber 140 may be connectedto the proximal end connector 114 and may have proximal ends thatconnect to a light fiber activation source via at least one of theplurality of ports 115. In some embodiments, the light fibers 140, 142may be configured to transmit light at a wavelength of 375 nanometers(nm) to 475 nm, and more specifically 450 nm that transmits through thedistal segment 130 and the first distal balloon 120. The light fibers140, 142 may emit light outside of the ultraviolet (UV) range of 10 nmto 400 nm. In some embodiments, the light first fiber 140 may bepositioned in the first light fiber lumen 158 and the second light fiber142 may be positioned in the second light fiber lumen 160.

In some embodiments, light from the light fibers 140, 142 may be unableto penetrate through a guidewire 144 forming a shadow 145 opposite thelight and beyond the guidewire 144. Accordingly, the light fibers 140,142 may each generate a respective light transmission area 146. Thelight fiber lumens 158, 160 are oriented substantially opposite oneanother minimizing the shadow 145 formed by the light impenetrableguidewire 144, permitting the transmission of light to penetrate thecircumference of the catheter shaft 104 from the first light fiber 140or the second light fiber 142. In another embodiment, the catheter shaft140 may include a single light fiber, and the guidewire may be removedfor light penetration to the outer tissue.

In some embodiments, the light fibers 140, 142 may be made from plasticcore and cladding. The refractive index of the core is high. Therefractive index of the cladding is low. A non-limiting example of thecore material may be polymethyl methacrylate (PMMA). A non-limitingexample of the cladding may be a silicone material. The light source maycontrol the wavelength and supplied power of the light fibers 140, 142.The pattern of the breaks in the cladding of the light fiber ensureuniform power distribution to the vessel wall. Longer lengths have adifferent pattern than shorter lengths. The distal lengths of claddingbreaks are matched to the length of the balloons.

As illustrated in FIGS. 3 and 6, the longitudinal fluid channels 124 andcircumferential fluid channels 126 may form a pattern that may beinterconnected. The interconnected longitudinal fluid channels 124 andcircumferential fluid channels 126 of the pattern generate a volume thatfluid may fill in the channels. The longitudinal fluid channels 124 andcircumferential fluid channels 126 form outermost radial surfaces (e.g.outer surface 127) and innermost radial surfaces (e.g. inner surface128). The outermost radial surfaces 127 may contact the vessel wall andmay shape or cast the vessel, propping it open without overstretching orsubstantially dilating the vessel wall.

As shown in FIG. 6, the innermost radial surfaces 128 permit fluid toflow longitudinally and circumferentially, following the directionalarrows, supplying fluid throughout the entire innermost surface 128 ofthe first distal balloon 120 for subsequent uniform delivery through thesecond distal balloon 122, as described below. The longitudinal channels124 facilitate longitudinal fluid flow along the flow direction arrows,and the circumferential channels 126 facilitate circumferential fluidflow along the flow direction arrows. The number of fluid channels (e.g.longitudinal channels 124 and circumferential channels 126), outermostradial surfaces 127, and innermost radial surfaces 128 may vary tooptimize delivery function and remain shaped and functional during theentire inflation pressure range for continuous fluid supply. In someembodiments, the longitudinal fluid channels 124 may permit apreferential material weakness for folding the balloon.

FIG. 7 illustrates the second distal balloon 122 may have a thickness194 forming an outside surface 195 and an inside surface 196. The insidesurface 196 forms a confined and isolated volume 170 in fluidcommunication with the proximal end 106 of the catheter shaft 104 and aplurality of slitted apertures 198. The second distal balloon 122 mayinclude material that is substantially translucent and elastic, capableof remaining in contact with the outermost radial surface 127 of thefirst distal balloon 120, acting as a covering or skin, during inflationand deflation of the second distal balloon 122. The second distalballoon 122 may include material that is a porous membrane (ePTFE)substantially non-translucent and elastic, capable of permittingsubstantial light transmittance, and capable of remaining in contactwith the outermost radial surface 127 of the first distal balloon 120,acting as a covering or skin, during inflation and deflation of thesecond distal balloon 122. The second distal balloon 122 may include aplurality of slitted apertures 198 which may be perforations thatpenetrate through thickness 194 of the wall of the second distal balloon122 in fluid communication from the inside surface 196 of the balloon122 to the outside surface 195 of the balloon 122.

Slitted apertures 198 may be arranged in a circumferential and/orlongitudinal pattern. The slitted apertures 198 in regions 197 that areradially aligned with the outermost radial surfaces 127 of the firstdistal balloon 120 and the catheter shaft 104, and substantially absentin regions 199 aligned with the innermost radial surfaces 128 where thelongitudinal fluid channels 124 and circumferential fluid channels 126are positioned. “Substantially absent” may refer to the slittedapertures being positioned away from the first distal balloon regions ofinnermost radial surfaces 128 where the longitudinal fluid channels 124and circumferential fluid channels 126 are positioned. This patternpermits the slitted apertures 198 of the second distal balloon 122 toremain in contact with the outermost radial surfaces 127 of the firstdistal balloon 120, sealing the slitted apertures 198 closed during theinflation and deflation of the first distal balloon 120. The slittedapertures 198 may only open and permit fluid flow upon subsequentinflation of the second distal balloon 122, inflation of the seconddistal balloon 122 lifts the slitted apertures 198 away from theoutermost radial surfaces 127 of the first distal balloon 120. Theinflation of the second distal balloon 122 moving the slitted apertures198 away from the outermost radial surfaces 127 allows the slittedapertures 198 to function as microvalves and selectively deliver fluidto the vessel wall. The second distal balloon 122 may include at leastone slitted aperture 198 with a maximum length substantially the same asthe length of the outermost surface 195 (i.e., eight outermost surfaces195, eight slitted apertures 198 the length of the outermost surface195). The number and length of the slitted apertures 198 may vary toaccommodate the desired function; however, the pattern must be followedfor proper operation, ensuring the absence of slitted apertures 198 nearthe longitudinal fluid channels 124 and circumferential fluid channels126 of the first distal balloon 120.

FIGS. 8A-8F illustrate an inflation sequence in accordance withembodiments of the present disclosure. Although the second distalballoon 122 is not specifically shown in FIGS. 8A-8F, the second distalballoon 122 is expanded by the fluid pressure generated by the fluidpatterns shown in FIGS. 8E and 8F.

Inflating the first distal balloon 120 forms a substantially invariablefluid channel structure covered by the second distal balloon 122 whichmay be elastic. As illustrated in FIGS. 8A-8C, the fluid 200 fillslongitudinal fluid channels 124 and circumferential fluid channels 126first, the fluid 200 filling between the innermost surface 128 and theoutermost surface 127 of the first distal balloon 120 and the internalsurface 196 of the second distal balloon 122, away from the slittedapertures 198 which are aligned with and contacting the outermostsurfaces 127 of the first distal balloon 120. Fluid pressure builds inthe volume between the innermost surface 128 and the outermost surface127 of the first distal balloon 120 and the internal surface 196 of thesecond distal balloon 122, which causes the elastic second distalballoon 122 to begin to move away from the outermost surfaces 127 of thefirst distal balloon 120, allowing fluid 200 to begin to flow onto theoutermost surfaces 127, as shown in FIG. 8D. As pressure continues tobuild, the second distal balloon 122 continues to expand, allowing fluid200 to flow uniformly around the outer surfaces 127 and fluid channelsof the first distal balloon 120 (FIG. 8E), until the second distalballoon 122 is fully expanded and fluid 200 begins flowing through theslitted apertures 198 (after FIG. 8F is achieved).

The fluid 200 may be a drug source and provide a therapeutic purposewhen functionalized with a light source at the proper wavelength.Following the path of least resistance, the inflation fluid 200 of thesecond distal balloon 122 will fill the circumferential channels 126 andlongitudinal fluid channels 124 of the first distal balloon 120. Absentslitted apertures 198 in the second distal balloon 122, in regions ofthe first distal balloon 120 innermost radial surfaces 128 or fluidchannels (e.g. 124, 126), the innermost radial surfaces 128 or fluidchannels 124 or 126 of the first distal balloon 120 will substantiallyfill with fluid 200. The slitted apertures 198 of the second distalballoon 122 remain in contact with the outermost radial surface 127 ofthe first distal balloon 120, sealed and closed. Once the first distalballoon fluid channels 124, 126 are filled, further inflation of thesecond distal balloon 122 will cause the material to expand, lifting theslitted apertures 198 away from the first distal balloon outermostsurfaces 127, opening and unsealing the slitted apertures 198 andpermitting fluid 200 to flow through the slitted apertures 198. Onceinflation has stopped, the fluid 200 will exit from the unsealed slittedapertures 198 until only the fluid channels 124, 126 of the first distalballoon are filled, permitting the inner surface 196 of the seconddistal balloon 122 to rest on the outermost radial surfaces 127 of thefirst distal balloon 120, once again closing and sealing the slittedapertures 198. In this manner, inflating and deflating the second distalballoon 122 may selectively control the delivery of the drug source,acting as a series of microvalves in “on” and “off” conditions.Similarly, the second distal balloon 122 may be a porous membranematerial with small pores under low pressure and larger pores underhigher pressure. The first distal balloon 120 operates and performs asdescribed. The second distal balloon 122 operates and performs asdescribed, filling fluid channels 124 and 126 before contacting theinner surface 196; except, the pores of the second distal balloon 122remain closed until the pressure builds enough to open the pores andpermit the drug to flow from the outer surface of the first distalballoon 120 to the outer surface of the second distal balloon 122,acting as a series of microvalves in “open” and “closed” conditions

The target area for a delivery of drug source may be a vessel of thecardiovascular system. The target area may be first prepared bypercutaneous transluminal angioplasty (PTA) or atherectomy to displaceor remove damaged vessel cellular debris. The catheter apparatus 100 isnot intended to replace PTA; the functional pressure of the first distalballoon 120 is only sufficient to prop open the vessel during drugfunctionalization. The first distal balloon 120 may be inflated, formingfluid channels (e.g. 124, 126); the outermost radial surfaces 127contacting the inner surface 196 of the second distal balloon 122. Thesecond distal balloon 122 is inflated with a drug source, the fluidchannels 124, 126 of the first distal balloon 120 fill first, followedby the lifting of the slitted apertures 198 off of the first distalballoon outermost radial surfaces 127, which uniformly delivers the drugsource to the vessel wall.

In the event slitted apertures 198 are positioned near a smaller vessel,side branch or collateral, only the drug from those slitted apertures198 will be lost to the smaller vessels. However, all the remainingslitted apertures 198 will deliver drug to their adjacent vessel wallssuch that drug is delivered uniformly to the vessel wall with minimalloss to other areas. In some embodiments, while the first distal balloon120 is inflated, propping open the vessel wall and shaping the vesseldiameter, the light source may be activated during or after drugdelivery.

The edges of the slitted apertures 198 may remain together and closedthe first distal balloon 120 and second distal balloon 122 are filledwith a drug source, allowing the first distal balloon 120 and seconddistal balloon 122 to nearly fill and inflate without loss of the drugsource. As the second distal balloon 122 volume fills and inflates, thepressure will increase, forcing the edges of the slitted aperture 198 toopen and allow the fluid to exit through the slitted apertures 198,reducing the balloon pressure. Similarly, as the volume andcorresponding pressure of the second distal balloon 122 is reduced fromfluid flowing out through the slitted apertures 198, the edges of theslitted aperture 198 may close together and may stop fluid flow throughthe slitted apertures 198 when they come into contact with the outersurfaces 127 of the first distal balloon 120. In this manner ofinflating and deflating the first distal balloon 120 and the seconddistal balloon 122 may control the delivery of the drug source as theslitted apertures 198 are opened and closed.

In some embodiments, the apparatus 100 may be capable of delivering twodrugs simultaneously. For example, the outside of the second distalballoon 122 may be coated with a first drug and a second drug may bedelivered through the slitted apertures 198. Accordingly, the first drugand the second drug may be different drugs. In some embodiments, thefirst drug and the second drug may be the same drug. In a non-limitingexample, the second distal balloon 122 inner or outer surface may becoated with Paclitaxel and infusing an aqueous drug or saline throughthe slits to the vessel wall.

While in this vessel supported position, a light source may be suppliedto the light fibers 140, 142 in the catheter shaft 104 for transmittancethrough the catheter shaft 104, through the first distal balloon 120 andthe second distal balloon 122, and into the vessel wall 182 aspreviously described.

There are several combinations for the local delivery of a drug source.For example, a solid drug may be coated on the outside surface of thesecond distal balloon 122 and an aqueous drug may be delivered throughthe slitted apertures 198 of the second distal balloon 122. The drug maybe the same, one solid and one aqueous, each penetrating the vessel walldifferently. The drugs may be complimentary, but different substances(e.g., one drug may cross-link collagen restoring vessel properties anda complimentary drug may be an antiproliferative reducing procedurerelated inflammation). The aqueous or solid drug may assist in thecapacity of an excipient or activate its counterpart through acontrolled reaction. The drugs may be dissimilar and non-complimentaryaffecting the vessel wall through substantially different methods ofaction. The drugs may be delivered by the same apparatus (e.g. 100) insequence, one after the other, or with a timed delay, or multiple timesat the same location or at subsequent locations multiple times,permitting the most effective treatment procedure. The drugs may befunctionalized with the light source simultaneously with the delivery(i.e., the light source remains on during the delivery of the drugthrough the slitted apertures 198). The drugs may be effective when thedrugs are near tissue components and functionalized by a light source.

In some embodiments, the drug is not cured or activated, but the drug isfunctionalized to cross-link with tissue proteins. The tissue proteins,the drug, and the light may be present to create a therapeutic effect.The functionalizing of the drug may not be time dependent, butinstantaneous, dependent on wavelength alone. The light powercompensates for losses through the light fiber, two balloons, and tissuewall and may be balanced to avoid heat buildup during therapy.

In some embodiments, the apparatus 100 may provide a therapy utilizingmultiple aqueous drugs with different methods of action. One drug may bedelivered first and functionalized with the light fibers while thevessel is propped open, and subsequently another drug withantiproliferation capabilities may be delivered and not functionalizedwith the light fibers, and yet another drug with anti-inflammatoryproperties may be subsequently delivered providing a valuablecombination of beneficial drugs without compromising one for the other.

Additionally, therapeutic agents useful with the device of the presentdisclosure include any one of or a combination of several agents whichare gas, liquid, suspensions, emulsions, or solids, which may bedelivered or collected from the vessel for therapeutic or diagnosticpurposes. Therapeutic agents may include biologically active substances,or substances capable of eliciting a biological response, including, butnot limited to endogenous substances (growth factors or cytokines,including, but not limited to basic fibroblast growth factor, acidicfibroblast growth factor, vascular endothelial growth factor, angiogenicfactors, microRNA), viral vectors, DNA capable of expressing proteins,sustained release polymers, and unmodified or modified cells.Therapeutic agents may include angiogenic agents which induce theformation of new blood vessels. Therapeutic agents may also includeanti-stenosis or anti-restenosis agents which are used to treat thenarrowing of blood vessel walls. Therapeutic agents may includelight-activated agents such as light-activated anti-stenosis orlight-activated anti-restenosis agents that may be used to treat thenarrowing of blood vessel walls.

Accordingly, apparatus 100 is multifunctional, providing drug deliverycontrol in open and closed positions, and propping open a vessel wallforming a shape during drug functionalizing with a light source of aspecific wavelength outside of the ultraviolet (UV) range (10 nm to 400nm).

Another embodiment of this disclosure includes an exemplary method oftissue restoration in a blood vessel of a subject. The method mayinclude providing a catheter into the blood vessel. In some embodiments,the catheter may include the features of apparatus 100 described above.For example, the catheter may include a catheter shaft (e.g. cathetershaft 104) extending from a proximal end (e.g. proximal end 106) to adistal tip (e.g. distal tip 110). A first distal balloon (e.g. firstdistal balloon 120) may be positioned on a translucent distal segment(e.g. distal segment 130) of the catheter shaft proximal to the distaltip, the first distal balloon in fluid communication with a drug sourcevia a first lumen (e.g. first distal balloon inflation lumen 150). Thefirst distal balloon may include a translucent material and bepositioned inside of an concentric with a second distal balloon (e.g.second distal balloon 122), a plurality of longitudinal channels (e.g.longitudinal channels 124) recessed from a plurality of outermost radialsurfaces (e.g. outermost radial surfaces 127) of the first distalballoon, a plurality of circumferential channels (e.g. circumferentialfluid channels 126) recessed from the outermost radial surfaces of thefirst distal balloon. The second distal balloon (e.g. second distalballoon 122) may be in fluid communication with a second lumen (e.g.second distal balloon inflation lumen 154) separate from the firstlumen. The catheter may further include a first light fiber (e.g. lightfiber 140) and a second light fiber (e.g. light fiber 142) eachpositioned in the catheter shaft and extending through the translucentdistal segment.

The method may further include supplying a drug from the drug source tothe first distal balloon, delivering the drug to the treatment areathrough the slitted apertures (e.g. slitted apertures 198), activatingthe first light fiber and the second light fiber, thereby providinglight transmission through the distal segment, the first distal balloon,and the second distal balloon to activate the drug in the treatmentarea. The light transmission to the treatment area may activate theNatural Vascular Scaffolding (NVS), which may be activated by light. Theexpansion of the first distal balloon may shape the treatment area (e.g.vessel) as desired.

The method may further include gradually filling the drug into a volumeof the longitudinal channels and circumferential channels between aninside surface of the second distal balloon and an outside surface ofthe first distal balloon, and expanding the second distal balloon,thereby moving the slitted apertures away from the outermost radialsurfaces of the first distal balloon.

Accordingly, the apparatus and methods described herein provide thedelivery of NVS to a treatment area (e.g. a vessel) and providerestoration to that treatment area using the apparatus or according tothe methods described above. The apparatus and method described aboveprovide concurrently treating the vessel with one or more drugs (e.g.with Paclitaxel and NVS) with minimal loss to other vessels, scaffoldingand casting the vessel, and light activation of the one or more drugsdelivered to the treatment area. These advantages can be accomplishedutilizing the apparatus and methods described herein.

According to embodiments of the present disclosure, NVS may includedimeric naphthalmides as described in U.S. Pat. No. 6,410,505 B2, andU.S. Provisional Patent Application No. 62/785,477. For example, adimeric naphthalimide compound,2,2′-((ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))bis(6-((2-(2-(2-aminoethoxy)ethoxy)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione),also known as 10-8-10 dimer,6-[2-[2-(2-aminoethoxy)ethoxy]ethylamino]-2-[2-[2-[2-[6-[2-[2-(2-aminoethoxy)ethoxy]ethylamino]-1,3-dioxobenzo[de]isoquinolin-2-yl]ethoxy]ethoxy]ethyl]benzo[de]isoquinoline-1,3-dione;2,2′-[1,2-ethanediylbix(oxy-2,1-ethanediyl)]bis[6-({2-[2-(2-aminoethoxy)ethoxy]ethyl}amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione];and 1H-benz[de]isoquinoline-1,3(2H)-dione,2,2′-[1,2-ethanediylbis(oxy-2,1-ethanediyl)]bis[6-[[2-[2-(2-aminoethoxy)ethoxy]ethyl]amino]-(9Cl),and herein referred to as Compound of Formula (I), has been disclosed.Id.

The foregoing description has been presented for purposes ofillustration. It is not exhaustive and is not limited to precise formsor embodiments disclosed. Modifications and adaptations of theembodiments will be apparent from consideration of the specification andpractice of the disclosed embodiments. For example, the describedimplementations include hardware and software, but systems and methodsconsistent with the present disclosure can be implemented as hardwarealone. In addition, while certain components have been described asbeing coupled to one another, such components may be integrated with oneanother or distributed in any suitable fashion.

Moreover, while illustrative embodiments have been described herein, thescope includes any and all embodiments having equivalent elements,modifications, omissions, combinations (e.g., of aspects across variousembodiments), adaptations and/or alterations based on the presentdisclosure. The elements in the claims are to be interpreted broadlybased on the language employed in the claims and not limited to examplesdescribed in the present specification or during the prosecution of theapplication, which examples are to be construed as nonexclusive.Further, the steps of the disclosed methods can be modified in anymanner, including reordering steps and/or inserting or deleting steps.

The features and advantages of the disclosure are apparent from thedetailed specification, and thus, it is intended that the appendedclaims cover all systems and methods falling within the true spirit andscope of the disclosure. As used herein, the indefinite articles “a” and“an” mean “one or more.” Similarly, the use of a plural term does notnecessarily denote a plurality unless it is unambiguous in the givencontext. Words such as “and” or “or” mean “and/or” unless specificallydirected otherwise. Further, since numerous modifications and variationswill readily occur from studying the present disclosure, it is notdesired to limit the disclosure to the exact construction and operationillustrated and described, and accordingly, all suitable modificationsand equivalents may be resorted to, falling within the scope of thedisclosure (e.g., slitted apertures, apertures, perforations may be usedinterchangeably maintaining the true scope of the embodiments)

Other embodiments will be apparent from consideration of thespecification and practice of the embodiments disclosed herein. It isintended that the specification and examples be considered as exampleonly, with a true scope and spirit of the disclosed embodiments beingindicated by the following claims.

1-20. (canceled)
 21. An apparatus comprising: a catheter shaft extendingfrom a proximal end to a distal tip; a first distal balloon positionedon a translucent distal segment of the catheter shaft proximal to thedistal tip and positioned inside of and concentric with a second distalballoon, the first distal balloon in fluid communication with a drugsource via a first lumen, the first distal balloon comprising: atranslucent material; a plurality of circumferential channels recessedfrom the outermost radial surfaces of the first distal balloon; and atleast one light fiber positioned in the catheter shaft and extendingthrough the translucent distal segment.
 22. The apparatus of claim 21,wherein the second distal balloon comprises a plurality of slittedapertures radially aligned with a plurality of outermost radial surfacesof the first distal balloon, the slitted apertures selectivelycommunicate a drug from the first distal balloon to a treatment area ofa subject.
 23. The apparatus of claim 22, wherein the slitted aperturesare positioned away from the circumferential channels of the firstdistal balloon.
 24. The apparatus of claim 22, wherein the slittedapertures of the second distal balloon remain in contact with theoutermost radial surfaces of the first distal balloon, sealing theslitted apertures closed during inflation and deflation of the firstdistal balloon.
 25. The apparatus of claim 22, wherein during inflationof the second distal balloon, the drug fills between an inside surfaceof the second distal balloon and an outside surface of the first distalballoon, gradually filling the circumferential channels.
 26. Theapparatus of claim 25, wherein a pressure of the drug between the insidesurface of the second distal balloon and the outside surface of thefirst distal balloon increases and inflates the second distal balloon,the increased pressure forces edges of the slitted apertures to openapart thereby reducing the pressure.
 27. The apparatus of claim 22,wherein inflation of the second distal balloon moves the slittedapertures away from the outermost radial surfaces of the first distalballoon allowing the slitted apertures to open and permit fluid flow tothe treatment area.
 28. The apparatus of claim 21 wherein the distalsegment, the first distal balloon, and the second distal balloon are atleast partially transparent.
 29. The apparatus of claim 21 wherein theat least one light fiber provides light activation through the distalsegment, the first distal balloon, and the second distal balloon. 30.The apparatus of claim 21 wherein the circumferential channels arenon-deformable and are configured to assist to provide uniform drugdelivery through the second distal balloon.
 31. The apparatus of claim21 wherein the second distal balloon comprises material that isconformable to the morphology of the vessel wall.
 32. A method of tissuerestoration in a blood vessel of a subject comprising: providing acatheter into the blood vessel, the catheter comprising: a cathetershaft extending from a proximal end to a distal tip; a first distalballoon positioned on a translucent distal segment of the catheter shaftproximal to the distal tip and positioned inside of and concentric witha second distal balloon, the first distal balloon in fluid communicationwith a drug source via a first lumen, the first distal ballooncomprising: a translucent material; a plurality of circumferentialchannels recessed from the outermost radial surfaces of the first distalballoon; the second distal balloon comprises a plurality of slittedapertures radially aligned with a plurality of outermost radial surfacesof the first distal balloon, the slitted apertures selectivelycommunicate a drug from the first distal balloon to a treatment area ofa subject; and at least one light fiber positioned in the catheter shaftand extending through the translucent distal segment; supplying the drugfrom the drug source to the first distal balloon; delivering the drug tothe treatment area through the slitted apertures; and activating the atleast one light fiber thereby providing light transmission through thedistal segment, the first distal balloon, and the second distal balloonto activate the drug in the treatment area.
 33. The method of claim 32further comprising: gradually filling the drug into a volume of thecircumferential channels between an inside surface of the second distalballoon and an outside surface of the first distal balloon; expandingthe second distal balloon, thereby moving the slitted apertures awayfrom the outermost radial surfaces of the first distal balloon.
 34. Themethod of claim 32, wherein the slitted apertures are positioned awayfrom the circumferential channels of the first distal balloon.
 35. Themethod of claim 32, further comprising contracting the second distalballoon as the drug is delivered through the slitted apertures.
 36. Themethod of claim 35, wherein contracting the second distal balloon movesthe second distal balloon into contact with the outermost radialsurfaces of the first distal balloon and closes the slitted apertures,causing drug delivery to stop.
 37. The method of claim 33, wherein apressure of the drug between the inside surface of the second distalballoon and the outside surface of the first distal balloon increasesand inflates the second distal balloon, the increased pressure forcesedges of the slitted apertures to open apart thereby reducing thepressure.
 38. The method of claim 32, wherein the at least one lightfiber provide light activation through the distal segment, the firstdistal balloon, and the second distal balloon.
 39. The method of claim32, wherein the slitted apertures are positioned away from thecircumferential channels of the first distal balloon.
 40. An apparatuscomprising: a catheter shaft extending from a proximal end to a distaltip; a first distal balloon positioned on a translucent distal segmentof the catheter shaft proximal to the distal tip and positioned insideof and concentric with a second distal balloon, the first distal balloonin fluid communication with a drug source via a first lumen, the firstdistal balloon comprising: a translucent material; a plurality ofcircumferential channels recessed from the outermost radial surfaces ofthe first distal balloon; at least one light fiber each positioned inthe catheter shaft and extending through the translucent distal segment;and wherein the drug source is configured to provide at least one drugto the first distal balloon via the first lumen and during inflation ofthe second distal balloon, a fluid fills between an inside surface ofthe second distal balloon and an outside surface of the first distalballoon, and gradually fills the circumferential channels.